diff --git a/src/test/java/ch/zhaw/pm2/racetrack/CarTest.java b/src/test/java/ch/zhaw/pm2/racetrack/CarTest.java
index 5f0c462..3468cbf 100644
--- a/src/test/java/ch/zhaw/pm2/racetrack/CarTest.java
+++ b/src/test/java/ch/zhaw/pm2/racetrack/CarTest.java
@@ -11,38 +11,62 @@ import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.*;
 
+/**
+ * Tests for Class Car
+ */
 class CarTest {
+
     Car car;
+
+    // Default coordinates for tests
     int DEFAULT_X = 10;
     int DEFAULT_Y = 10;
 
+    /**
+     * Create a new Car Object and set Position to a defined Default Position
+     */
     @BeforeEach
     void setUp() {
         car = new Car('a', new PositionVector(DEFAULT_X, DEFAULT_Y));
     }
 
+    /**
+     * Method to check nextPosition with coordinates as int
+     *
+     * @param x the expected value for x coordinate
+     * @param y the expected value for y coordinate
+     */
+    void CheckNextPosition(int x, int y) {
+        assertEquals(new PositionVector(x, y), car.nextPosition());
+    }
 
+    /**
+     * - checks if the position of the car can be set and saved correctly with valid positions.
+     * - checks if an exception is throwed and position keeps unchanged if invalid coordinates are entered.
+     */
     @Test
     void setPosition() {
         CheckNextPosition(DEFAULT_X, DEFAULT_Y);
 
+        // List of valid Positions
         List<PositionVector> validPositions = new ArrayList<>();
         validPositions.add(new PositionVector(20, 20));
         validPositions.add(new PositionVector(0, 0));
         validPositions.add(new PositionVector(20, 0));
         validPositions.add(new PositionVector(0, 20));
 
-        for(PositionVector positionVector : validPositions) {
+        for (PositionVector positionVector : validPositions) {
             car.setPosition(positionVector);
             assertEquals(positionVector, car.nextPosition());
         }
 
+        // List of invalid positions.
         List<PositionVector> invalidPositions = new ArrayList<>();
         invalidPositions.add(new PositionVector(0, -20));
         invalidPositions.add(new PositionVector(-20, 0));
         invalidPositions.add(new PositionVector(-20, -20));
 
-        for(PositionVector positionVector : invalidPositions) {
+        for (PositionVector positionVector : invalidPositions) {
             boolean exception = false;
             try {
                 car.setPosition(positionVector);
@@ -51,62 +75,73 @@ class CarTest {
             }
             assertTrue(exception);
 
+            // position should keep unchanged
             CheckNextPosition(DEFAULT_X, DEFAULT_Y);
         }
     }
 
 
-
+    /**
+     * Checks if the methods accelerate and move are working correctly with acceleration in all directions.
+     * Checks also if velocity is calculated correctly if method accelerate is called a second time.
+     */
     @Test
     void movement() {
+        // add all possible directions in a List
+        List<PositionVector.Direction> directions = Arrays.asList(PositionVector.Direction.values());
+
+        //position shouldn't be changed because velocity should be 0.
         car.move();
         CheckNextPosition(DEFAULT_X, DEFAULT_Y);
 
-        List<PositionVector.Direction> directions = Arrays.asList(PositionVector.Direction.values());
-
-        for (PositionVector.Direction direction1 : directions){
+        for (PositionVector.Direction direction1 : directions) {
 
+            //create a new instance of Car with default coordinates and velocity 0.
             setUp();
-            int nextPosX = DEFAULT_X;
-            int nextPosY = DEFAULT_Y;
+
+            //variables to save the actual expected result of method nextPosition
+            int ExpectedNextPosX = DEFAULT_X;
+            int ExpectedNextPosY = DEFAULT_Y;
 
             car.accelerate(direction1);
-            nextPosX += direction1.vector.getX();
-            nextPosY += direction1.vector.getY();
-            CheckNextPosition(nextPosX, nextPosY);
+            ExpectedNextPosX += direction1.vector.getX();
+            ExpectedNextPosY += direction1.vector.getY();
+            CheckNextPosition(ExpectedNextPosX, ExpectedNextPosY);
 
             car.move();
-            nextPosX += direction1.vector.getX();
-            nextPosY += direction1.vector.getY();
-            CheckNextPosition(nextPosX, nextPosY);
+            ExpectedNextPosX += direction1.vector.getX();
+            ExpectedNextPosY += direction1.vector.getY();
+            CheckNextPosition(ExpectedNextPosX, ExpectedNextPosY);
 
             for (PositionVector.Direction direction2 : directions) {
                 car.accelerate(direction2);
-                nextPosX += direction2.vector.getX();
-                nextPosY += direction2.vector.getY();
-                CheckNextPosition(nextPosX, nextPosY);
+                ExpectedNextPosX += direction2.vector.getX();
+                ExpectedNextPosY += direction2.vector.getY();
+                CheckNextPosition(ExpectedNextPosX, ExpectedNextPosY);
 
                 car.move();
-                nextPosX += direction1.vector.getX();
-                nextPosY += direction1.vector.getY();
-                nextPosX += direction2.vector.getX();
-                nextPosY += direction2.vector.getY();
-                CheckNextPosition(nextPosX, nextPosY);
-
+                ExpectedNextPosX += (direction1.vector.getX() + direction2.vector.getX());
+                ExpectedNextPosY += (direction1.vector.getY() + direction2.vector.getY());
+                CheckNextPosition(ExpectedNextPosX, ExpectedNextPosY);
             }
-
         }
     }
 
 
+    /**
+     * test for methods crash and isCrashed. checks if state crashed is set and returned correctly.
+     */
     @Test
     void crash() {
         assertFalse(car.isCrashed());
         car.crash();
         assertTrue(car.isCrashed());
-
     }
 
+    /**
+     * test for methods setMoveStrategy. Checks if the MoveStrategy Object is saved and returned correctly
+     * with all Types of MoveStrategy.
+     */
     @Test
     void MoveStrategy() {
         MoveStrategy moveStrategy;
@@ -127,10 +162,4 @@ class CarTest {
         car.setMoveStrategy(moveStrategy);
         assertEquals(moveStrategy, car.getMoveStrategy());
     }
-
-
-
-    void CheckNextPosition(int x, int y) {
-        assertEquals(new PositionVector(x, y), car.nextPosition());
-    }
 }